Holland international Janmaat, who joined Newcastle in July 2014 from Feyenoord, has signed a four-year contract at Vicarage Road.

The 27-year-old said in quotes reported on watfordfc.com: "I'm really happy to be here, it's a new adventure for me. I was really pleased that Watford showed interest in me because I wanted to play in the Premier League.

"We [Newcastle] lost three times to Watford last season. They had a good season and I hope we can do the same again this year.

"The club is showing great ambition and wants to improve and I want to be part of that."

Janmaat made 77 appearances in all competitions for Newcastle, scoring four goals. His final outing for the Magpies came in a 2-1 home defeat at the hands of Huddersfield Town earlier this month.